Extended Battery for Xperia X10 mini Pro?

[Cadillac.Cowboy]

I just purchased an Xperia X10 mini pro and whilst I absolutely adore the smartphone, the usage times aren't too crash-hot... A bit of research (which probably would have come in handy prior to my purchase!) shows that usage times are a common issue with this specific handset.

Anyway, as the subject suggests, I would like to purchase an extended battery for my Xperia X10 mini pro, something with a little longer usage times... Any ideas?